Gear-wheel pump



Sept. 17,1946. 4 A. G. F. WALLGREN' .-2,4o7,753

GEAR WHEEL PUMP I Fiied Oct. 27, 1941 2 She ets-Sheet 2 Patented Sept.17, 1946 GEAR-WHEEL PUMP August Gunnar Ferdinand Wallgren, Eskilstuna,

Sweden, assignor to Aktieholaget Bolinder- Munktell, Eskilstuna, Sweden,a corporation of the Kingdom of Sweden Application October 27, 1941,Serial No. 416,777 In Sweden August 15, 1940 4 Claims. 1

This invention relates to gear wheel pumps intended primarily for waterimpurified by mud, sand and the like, such as sea water which isutilized, for instance, for the cooling of marine engines. Pumps of thegear wheel type have, among other things, the advantage over thereciprocating pumps hitherto used that they may be operated at a higherrotary speed, by reason of which they have smaller dimensions. It hashitherto not been possible, however, to utilize this advantage of gearwheel pumps, inasmuch as the particles entrained with th water wear ordamage the bearings as well as the teeth of the pump, so that the pumpis rendered inserviceable in a short time.

. The main objects of the invention are to obviate this drawback and toprovide a gear whee pump for impurified water, being entirely safe inoperation and the capacity of which remains unaltered even after thepump has been in operation for a very longtime.

Further objects and advantages of the invention will be apparent fromthe followingdescription considered in connection with the accompanyingdrawings which form a part of this specification, and of which: I

Fig. 1 shows a section through a combined gear wheel pump for water andoil constructed in accordance with the invention;

Fig. 2 is an endwise view of the pump in a plane taken on line IIII inFig. 1;

Fig, 3 is an endwise view of the pump in a plane taken on line III-IIIin Fig. 1.

In the embodiment as illustrated, the gear wheel pump is intended to bemounted in a motor frame It, which is provided with an opening overwhich the pump housing I I is placed. The pump housing may be connectedwith the frame I I by means of bolts I2. The pump is formed with a pairofgear wheels I3 for the pumping of oil and with a pair of gear wheelsI4 for the pumping of water. The oil circulates between the pump and thevarious lubricating and cooling places in the motor (not shown), and thewater i taken in from the outside for direct or indirect cooling of themotor cylinders in a well known manner. A shaft I5 driven from the motorshaft is mounted in two bearings IS, IT. The one gear wheel I3 for theoil pump is arranged between the bearingsIIi and II. The one gear wheelI4 of the water pump is carried by an overhanging portion of the shaftI5 projecting outside the bearing I I. The two other gear wheels of theoil and water pumps are rigidly connected to a shaft I8, which ismounted on both sides of the gear wheel I3 of the oil pump in bearings I9, 20. The gear wheel of the water pump is in this case also arranged onthe overhanging end portion of the shaft outside the bearing 20. Theshaft I5 drives the shaft I8 over the gear wheels I3, while the pair ofgear wheels I4 has a clearance between the teeth.- This clearance is ofsufficient magni-- tude to prevent sand particles and the like en.-

covers bear on the lateral surfaces of the respec tive gear wheels withthe desired clearance, they are provided with shoulders 32- adapted toabut against each other when the bolts 21 are-tightened up. Thesaidclearances which are of material importance for theproperfunctioning of.

the gear wheel pumps, will thus be independent of the degree ofcompression of the packings 28 from case to case.

It is of material importance for the proper functionin of the pump thatthe water contained in the compartment 24 is prevented from entering thebearings I1, 20. Furthermore, leakage of oil from the oil pump into thewater pump is not desirable. To this end, two-pacikings 32 are arrangedbetween the gear wheels I4 and the housing II, as appears from 'Fig; 1.-The hubs 33 of the gear wheels I4 are located for this purpose at theone (external) side of the toothed rims;

so that the requisite space is obtained for the packings. The hubs 33are connected without any play with the shafts I5, I8 with the aid ofsleeves 34, the inner surfaces of which are coni cal, as are the endportions of the shafts and 'which are retainedby means of screws 35.Provided between the hubs 33 and shafts are car- 7 rier pins 36. Thehubs are connected in a liquidtight manner with the shafts, so thatwater caninside of the gear wheel I4 by means of a spiral spring 39. Thepacking rings 38 are placed in a manner such that the pressure of therespective media is added to the pressure of the spiral spring to bringabout a suitable sealing pressure in the sliding surface between therings and the gear wheels I4. Between the packings, there is a space 40communicating with the atmosphere over passages 4 I. Water, which maythus penetrate from the gear wheel compartment 24 into the space 40, isled off through the said passages 4|, and cannot reach the bearings I1,29. If, on the other hand, oil would happen to seek its way out throughthe other packing 32, the oil will also be led off through the passages4!. The compartments 22 and 24 are entirely separated from each other,as' will be understood from the above.

The teeth of the pair of gear wheels I 4 may be covered with a layer ofrubber 44. If sand. particles or the like would happen to be entrainedwith the water, these particles being of a greater diameter than theplay between the teeth, said rubber layer will prevent damaging of theteeth. The rubber permits of being deformed without disadvantage whilethe sand grains are passing between the teeth. It will be found suitableto form the gear wheels of the water pump with angular teeth. In theembodiment shown, these gear wheels are of a greater width than the gearwheels l3 of the oil pump.

' Otherwise, the pumps are constructed in a Well known manner withinlets and outlets forthe respective media. The water is taken inthrough a conduit 46 to the suction side 41. of the water pump. From thepressure side 48 of the pump, the water escapes through a passage 48aand a conduit 49 (Figs. 2 and 3) to the motor. Ihe cover 26 is providedwith a partition between the suction and pressure sides of the waterpump.

The oil is sucked in to the suction side 52 of the oil pump through aconduit 53, and escapes from the pressure side 54 thereof through a conduit 55. Otherwise, the pumps may be constructed in any known manner,and may be provided with passages, for example, beside the toothengagement of the respective" pair of gear wheels, to lead off theliquid which is present between the teeth when the latter enter intoengagement with one another. Such means are irrelevant to the invention,and for this reason they are not described in detail here.

The invention may be modified in many respects, without departing fromthe basic idea of the invention. Those parts of the pump which come intocontact with the water, which may be salt water, are preferably madefrom non-corroding material, such as stainless steel.

What I claim'i's:

1. In a gear wheel pump for pumping liquid containing entrained solidparticles, a housing having end' walls and partition means for dividingthehousinginto two compartments, a pair of parallel shafts, bearingmeansfor journal-ling said shafts in said partition and in one of said endwalls, a pair of accurately meshing gears mounted on said shafts in thecompartment between said partition means and said one of said end walls,a pair of toothed circular gears mounted on said shafts in the othercompartment and in overhung relation with respect to the bearingsin saidpartition means, the last-mentioned gears having: sufficient playbetween them to accommodate the entrained solid particles, said othercompartment being formed with inlet and outlet openings, and packingmeans between said partition means and said last-mentioned gears forpreventing leakage of fluid between said other compartment and thebearing in said partition means.

2. In a gear wheel pump for pumping liquid containing entrainedsolid'particle's, a housing having end Walls and a partitionthere'betwe'en for dividing the housing into two compartments, a pair ofbosses extending from saidv partition into one of said compartments, apair) of parallel shafts, bearing means in said bosses and in the end.wall which bounds the other of said. compartments for rotatably mountingsaid shafts,

each of said shafts having an over-hung end extending into said onecompartment, a pair of accurately meshing gears mounted on said shaftsin the other compartment, a pair of toothed circular hollow gearssecured to the over-hung ends of said shafts in aid one compartment andsurrounding said bosses, the last-mentioned gears having sufiicient playbetween them to accommo date the entrained solid particles, said othercompartment being formed. with inlet and outlet openings, said hollowgears being in fluid tight relation to the respective shafts, andpacking means disposed between the interiors of said hollow gears andsaid bosses for preventing leakage between said on compartment and thebearing means in said bosses.

3. In a gear wheel pump for pumpin liquid containing entrained solidparticles, a housing having end walls and a partition therebetween fordividing the housing into two compartments, a pair of bosses extendingfrom said partition into one of said compartments, a pair of parallelshafts, bearing means in said bosses and in the end wall which boundsthe other of said compartments for rotatably mounting said shafts,

each shaft having an over-hung end in said one compartment, a pair ofaccurately meshing gears mounted on said shafts in the othercompartment, a pair of toothed circular hollow gears secured to theover-hung ends of said shafts in said one compartment and surroundingsaid bosses, the last-mentioned gears having sufficient play betweenthem to accommodate the entrained solid particles, said othercompartment being formed with inlet and outl t openings, said ends ofthe shafts being conical, conical sleeves disposed be tween said conicalends and the hubs of said hollow gears, bolts having threaded engagementwith tapped holes in said conical ends for forcing said sleeves betweenthe shafts and the hubs to effect a liquid-tight seal therebetween, andpacking means disposed between the interiors of said hollow gears andsaid bosses for preventing leakage between said one compartment and thebearing means in said bosses.

4. In a gear wheel pump for pumping liquid containing entrained solidparticles,'a housing having end walls and aparti'tion therebetween fordividing. the housing into two compartments, a pair of bosses extendingfrom said partition into one of said compartments, a pair of parallelshafts, bearing means in said bosses and in-the' end wall which boundsthe other of said compartmentslfor rotatably mountingsaid' shafts, eachshaft having an over-hung end in said one compartment, a pair ofaccurately meshing gears" mounted on said shafts in the othercompartment, a pair of toothed circular hollow gears secured to theover-hungends of said shafts in said one compartment and surroundingsaid bosses, the last-mentioned. gears having sufiicient play betweenthem to accommodate the entrained solid particles, said othercompartment being formed 7 with inlet and outlet openings, and a pair ofaxially spaced packing means between the interior of each of said hollowgears and the respective boss which. the gear surrounds, and meansforming a drainage passageway from the space between each pair ofpacking means.

AUGUST GUNNAR FERDINAND WALLGREN'.

